Beneficial effects of nickel promoter on the efficiency of alumina-supported Co3O4 catalysts for lean methane oxidation
In this work bimetallic Ni catalysts supported over Co-Al2O3 and monometallic Co-Al2O3 and Ni-Al2O3 catalysts were examined for the complete oxidation of methane. With a 30 % total metallic loading, the samples were synthesized by a sequential precipitation route. All samples were characterized by n...
| Autores: | , , , |
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| Formato: | artículo |
| Fecha de publicación: | 2022 |
| País: | España |
| Recursos: | Universidad del País Vasco |
| Repositorio: | Addi. Archivo Digital para la Docencia y la Investigación |
| OAI Identifier: | oai:addi.ehu.eus:10810/59371 |
| Acesso em linha: | http://hdl.handle.net/10810/59371 |
| Access Level: | acceso abierto |
| Palavra-chave: | lean methane oxidation cobalt catalysts bimetallic Ni-Co catalysts Nickel cobaltite vehicular natural gas Oxygen mobility Nickel promoter |
| Resumo: | In this work bimetallic Ni catalysts supported over Co-Al2O3 and monometallic Co-Al2O3 and Ni-Al2O3 catalysts were examined for the complete oxidation of methane. With a 30 % total metallic loading, the samples were synthesized by a sequential precipitation route. All samples were characterized by nitrogen physisorption, X-ray fluorescence, X-ray diffraction, Raman spectroscopy, scanning electron microscopy, scanning-transmission electron microscopy, X-Ray photoelectron spectroscopy, and temperature-programmed reduction with hydrogen and methane. Their catalytic performance was investigated in the temperature range of 200-600 degrees C with a space velocity of 60.000 h-1. The bimetallic catalysts showed a better behavior in the oxidation reaction than the monometallic counterparts, mainly due to the good dispersion of Ni on the surface of the Co-Al2O3 samples. This has enabled the insertion of Ni2+ ions into the cobalt spinel lattice, which in turn provoked an increase in the amount of Co3+ species, and a subsequent enhanced mobility of oxygen species in the spinel. In this sense, the 5Ni/25Co catalyst showed the best performance, thus reducing the value of the T50 by 25 degrees C with respect to the monometallic catalysts. |
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